Which of the following processes helps redirect phagocytes to the site of an infection?

Chemotaxis is the process by which phagocytes are directed to the site of an infection in response to chemical signals. When tissues are damaged or infected, they release signaling molecules called chemokines. These molecules create a chemical gradient, which phagocytes detect and follow to the source of these signals. This movement toward higher concentrations of chemokines allows immune cells like macrophages and neutrophils to reach the area where pathogens are present, thereby enhancing the body's immune response to effectively combat the infection.

The other processes listed play different roles in the immune system. For instance, lysis refers to the breaking down or destruction of cells, often by complement proteins, rather than guiding immune cells. Vasodilation is the widening of blood vessels that occurs during inflammation, increasing blood flow to the area, which can help bring more immune cells but does not specifically guide their movement. Opsonization involves marking pathogens for destruction by immune cells but does not directly influence the movement of phagocytes to the infection site.